If she had.

.

.

a cruel look, that would have made her shudder, gleamed in Chauvelin's keen, pale eyes.

If she had played him a trick, Armand St.Just would suffer the extreme penalty.
But no, no! of course she had not played him false! Fortunately the supper-room was deserted: this would make Chauvelin's task all the easier, when presently that unsuspecting enigma would enter it alone.